40 Hz声光刺激对创伤诱发大鼠焦虑样行为的干预作用

Effects of 40 Hz multisensory stimulation on trauma-induced anxiety-like behavior in rats

目的:探讨40 Hz声光刺激对创伤后应激障碍(PTSD)的焦虑样症状改善作用及其可能的分子机制。方法:将30只SD大鼠随机分为Control组、PTSD组、PTSD+40 Hz组,每组10只。采用SPS&S方法构建PTSD模型。PTSD+40 Hz组大鼠在构建模型后,施加声光刺激40 Hz 7 d。应用高架迷宫(EPM)和旷场试验(OFT)评估各组大鼠焦虑样行为,Western blot方法检测大鼠皮层和海马中BDNF、TrkB、SynapsinⅠ和PSD95的蛋白表达水平,实时荧光定量(RT-PCR)方法检测皮层和海马中BDNF mRNA表达水平,免疫荧光实验检测BDNF在皮层和海马中的分布情况。结果:与Control组比较,PTSD组大鼠在旷场试验中运动总距离和在中央区域停留时间明显下降(P<0.05),PTSD组大鼠在高架十字迷宫试验中进入开放臂次数占总进入次数百分比降低,运动总距离明显下降(P<0.05)。且海马、皮层脑区BDNF、TrkB、PSD95、SynapsinⅠ蛋白表达水平显著降低(P<0.01),BDNF的mRNA的表达水平显著降低(P<0.01),免疫荧光结果显示BDNF在CA1、DG和PFC脑区表达减少;与PTSD组比较,PTSD+40 Hz组大鼠在旷场试验中总路程和在中央区域停留时间明显上升(P<0.05),在高架十字迷宫试验中总路程和进入开放臂次数占总进入次数百分比明显上升(P<0.05),皮层、海马中BDNF、TrkB、PSD95、SynapsinⅠ蛋白表达水平明显升高(P<0.05),BDNF的mRNA的表达水平显著上升(P<0.05),免疫荧光结果显示BDNF在CA1、DG和PFC脑区表达增加。结论:40 Hz声光刺激可能通过调节BDNF-TrkB信号通路,改善皮层和海马中相关的神经元突触可塑性,从而缓解PTSD所致的焦虑样行为。

Objective:To investigate the effects of 40 Hz acousto-optical stimulation on anxiety like symptoms of post-traumatic stress disorder(PTSD),with emphasis on the possible molecular mechanism stimulation.Methods:Thirty SD rats were randomly divided into three groups:Control group,PTSD group and PTSD+40 Hz group,ten rats in each group.The SPS&S model was established in the rats of the PTSD group and PTSD+40 Hz group and,then PTSD+40 Hz group rats were stimulated with 40 Hz acousto-optical stimulation for 7 days.The behavior of anxiety was tested by elevated plus maze(EPM)and open field test(OFT).The expressions of brain-derived neurotrophic factor(BDNF),tyrosine kinase receptor B(TrkB),synapsinⅠand postsynaptic density protein 95(PSD95)in the rat prefrontal cortex(PFC)and hippocampus(HIP)were detected by Western blot.The mRNA transcription level of BDNF genes in the PFC and HIP was verified by real-time quantitative PCR(RT-PCR)and the distribution of BDNF in the PFC and HIP was determined by immunofluorescence.Results:Compared with the Control group,in the OFT the total distance and the time spending in the center,and in the EPM the total distance were decreased significantly(P<0.05),the number of entering into the open arm as a percentage of the total number of entering in two arms was decreased,and the expression levels of BDNF,TrkB,PSD95,Synapsin I protein in HIP and PFC,and the mRNA expression level of BDNF were reduced significantly(P<0.01),the immunofluorescence expression of BDNF was reduced in CA1,DG and PFC in the PTSD group rats;Compared with the PTSD group,the total distance and the time spending in the center in OFT(P<0.05),the total distance and the number of entering into the open arm as a percentage of the total number were increased significantly(P<0.05),the protein expression levels of BDNF,TrkB,PSD95,SynapsinⅠin the PFC and HIP,the mRNA expression level of BDNF were increased significantly(P<0.05),and the immunofluorescence expression of BDNF was increased significantly in CA1,DG and PFC in the PTSD+40 Hz group rats.Conclusion:40 Hz acousto-optical stimulation improves the formation of anxiety-like symptoms in rats with PTSD,which may be related to the synaptic plasticity influenced by BDNF-TrkB signaling pathway.